Hairy root cultures of Hyoscyamus muticus were established using Agrob
acterium rhizogenes ATCC 15834. In one out of 8 clones established, an
unusual root tip formation was observed after transfer of cultures fr
om half-strength Murashige and Skoog (1962) to White's medium (1939).
This phenomenon was associated with the production of a fine brownish
cell suspension culture. Hairy root development resumed after transfer
of the root tips from White to half-strength Murashige and Skoog medi
um. After plating the isolated brownish cells on hormone-free half-str
ength Murashige and Skoog or White solid medium, callus proliferation
was observed, and then redifferentiation of hairy roots occurred. The
polymerase chain reaction analysis of the H. muticus hairy root (clone
Z2) revealed that only the TL region of the T-DNA was integrated. The
growth and the production of five tropane alkaloids by this clone wer
e examined.